I'll get to it, but it helps to recall from the JPL news updates that the longer drive segments are generally about 30-35 m long.

My intention is to work on these maps at a standard scale with a 100 m grid superimposed. For areas with a lot of activity in a small area I will make more detailed maps at a larger scale, with a scale bar. The current map is between the two scales and I'm working on a different version for later, but right now I want to keep using this high contrast enlarged HiRISE base.

I know I have been assuming standard map orientation with North up, West to the left, etc., etc. Assuming the HiRISE image was taken in the afternoon, that would be consistent with the lighting.

Obviously, if we need to slew a map around for ease of demonstrating a particular route (as I can imagine may be needful when we get around to things like driving up a drywash cut canyonlike into the lower mound), it would be nice to see a compass rose somewhere, just for general orientation... and to help people like me find things when someone says "it's just west of the Sol 24 position."

-the other Doug

--------------------

“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain

Phil, slight differences on the sol locations aside, I see that the route on your map have a rotation of a few degrees (five?) when compared to mine and the same happens to the HiRISE background. I'm using the map-projected version of ESP_028401_1755 as a reference to register the polar mosaics and which is presumed to have North up. What do you think?

I'm using a map-projected image as well, but a pre-landing one chosen to be almost vertical (I don't have the file name with me right now). The incidence angle might cause an apparent rotation on sloping ground. And map projection might be based on a different central meridian or based on a preliminary ephemeris.

I hope this down and dirty Anaglyph provides some context for other people.

What I am not certain about is that this view is toward the NE. Also that mid distance could be described as a view of the northern portion of Glenelg. If I was a sailor I would describe my method as dead reckoning. I am not going to have time for much else. Back when Spirit was climbing Husband Hill I dead reckoned myself down and about 50 meters back out onto the plains before I was totally convinced I was completely lost!

NASA does mark the UTC time of the shots (one of the few bits of shooting conditions given), in this case 2012-09-18 09:38:11 UTC. An ephemeris program shows that the sun at the MSL site at that time was at 25.1° elevation and 275.1° azimuth, so the shadow of a vertical gnomon would be at 95°. Here's the image with the camera boresight and the approximate location of the right navcam shadow marked with red dots:

The separation between the dots is 392 pixels horizontally and 188 vertically. The navcams are specced at 0.0468° per pixel, so that's 18° in azimuth and 9° in elevation. So an estimate of the direction of the camera boresight is 95° - 18° = 77° azimuth and -25° + 9° = -16° elevation--assuming the mast is vertical, using plane geometry, level ground, etc. As a rough check, there are about 384 pixels (16.4°) from the boresight to the horizon, which works out to pretty close to 0°.

AARG! I am cursed. I really meant to write NE or ENE. The general direction to a region north of the Glenelg. The red dot on the JPL graphic PIA16148.I have the PIA1648 graphic on my desktop! I have MSL's location on sol 42 marked on that graphic! I am pretty certain that North is up in that graphic! That is generally the direction I thought I was looking. But that is not what I wrote!

I saw Bill Nye's presentation at PlanetFest where he talked about his father being a dialist (S.O.D.--sundial obsessive disorder). It was a charming talk. I had to laugh at his description of the "furniture" on dials like the obligatory motto, particularly his example of a French motto: "every hour injures, the last one kills." Ouch. MSL rejects French fatalism: "To Mars, To Explore."

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